Sonochemical Degradation of Gelatin Methacryloyl to Control Viscoelasticity for Inkjet Bioprinting

Abstract

Inkjet printing enables the mimicry of the microenvironment of natural complex tissues by patterning cells and hydrogels at a high resolution. However, the polymer content of an inkjet‐printable bioink is limited as it leads to strong viscoelasticity in the inkjet nozzle. Here it is demonstrated that sonochemical treatment controls the viscoelasticity of a gelatin methacryloyl (GelMA) based bioink by shortening the length of polymer chains without causing chemical destruction of the methacryloyl groups. The rheological properties of treated GelMA inks are evaluated by a piezo‐axial vibrator over a wide range of frequencies between 10 and 10 000 Hz. This approach enables to effectively increase the maximum printable polymer concentration from 3% to 10%. Then it is studied how the sonochemical treatment effectively controls the microstructure and mechanical properties of GelMA hydrogel constructs after crosslinking while maintaining its fluid properties within the printable range. The control of mechanical properties of GelMA hydrogels can lead fibroblasts more spreading on the hydrogels. A 3D cell‐laden multilayered hydrogel constructs containing layers with different physical properties is fabrictated by using high‐resolution inkjet printing. The sonochemical treatment delivers a new path to inkjet bioprinting to build microarchitectures with various physical properties by expanding the range of applicable bioinks.

Trends in Photopolymerizable Bioinks for 3D Bioprinting of Tumor Models

“…Inkjet printing can also provide opportunities to isolate single cells for drug screening and gene expression analysis for intratumoral heterogeneity analysis. Lee et al developed a nondestructive way for inkjet-based printing of 3–10 wt % GelMA using sonication to develop physiologically relevant constructs which can be adapted to several polymers for imparting the inkjet-based printability . PBs involving droplet-based bioprinting can facilitate the ability to miniaturize tumor models and recapitulate multicellular and cell–ECM interactions.…”

“…Lee et al developed a nondestructive way for inkjet-based printing of 3–10 wt % GelMA using sonication to develop physiologically relevant constructs which can be adapted to several polymers for imparting the inkjet-based printability. 70 PBs involving droplet-based bioprinting can facilitate the ability to miniaturize tumor models and recapitulate multicellular and cell–ECM interactions. Due to prolonged printing times, large-scale constructs can be difficult to recapitulate but provide an excellent opportunity to create multicellular spheroids to understand the complex cellular interactions and high throughput drug screening.…”

3D Inkjet-Bioprinted Lung-on-a-Chip

“…27,28 Inkjet offers the ability to construct thin and complex tissues layer-by-layer with different cell types by switching bioinks. 29 The highresolution patterning of living cells by inkjet has been demonstrated in 2D and 3D environments. 30,31 To date, bioprinting methods have been used for a wide range of tissues such as skin, 32,33 heart, 34 bladder, 35,36 and lung.…”

“…Bioprinting is a versatile technology that enables the automated fabrication of complex 3D-structured tissue models. , Computer-assisted deposition of cell-laden bioink enables the 3D fabrication of living tissues in a layer-by-layer manner, which allows high repeatability, reproducibility, and mass production by minimizing human intervention. , Among various bioprinting techniques, drop-on-demand inkjet bioprinting is capable of positioning living mammalian cells with micron resolution by ejecting a picolitre volume of the cell suspension, typically down to a single cell. , Inkjet offers the ability to construct thin and complex tissues layer-by-layer with different cell types by switching bioinks . The high-resolution patterning of living cells by inkjet has been demonstrated in 2D and 3D environments. , To date, bioprinting methods have been used for a wide range of tissues such as skin, , heart, bladder, , and lung. − Most of these studies have cultured bioprinted tissues under static conditions, so integrating with a microfluidic platform is a pivotal future step to mimic the in vivo environment by providing perfused culture conditions.…”

Predicting inkjet jetting behavior for viscoelastic inks using machine learning

“…The addition of a small amount of functional materials can significantly influence jet formation by inducing viscoelasticity. Increased viscoelasticity affects the drop velocity, forming a fine filament that might breaks up into multiple satellite droplets [20][21][22]. A further increase in viscoelasticity can even prevent the ink from being ejected at the nozzle, pulling it back into the nozzle or flooding the nozzle plate.…”